This invention relates to the fortification of eggs with iodine as a dietary supplement by contacting the eggs with a bathing solution having iodine and/or iodate ions in suspension, allowing the iodine to pass through the egg shell to the interior of the egg until an adequate internal iodine concentration of iodide or iodate salts is produced.
It is known that iodine is a dietary requirement for humans. Failure to obtain adequate amounts of iodine (typically less than 150 micrograms per day and especially less than 50 micrograms per day) may result in endemic goiter, with accompanying mental retardation in children. Seafood is a rich source of iodine. Consequently, people in areas far from the sea are encouraged to supplement their diet with about 400 micrograms of iodine per day. This may be in the form of 0.002% to 0.01% iodized table salt.
Ingestion of iodine via iodized salt has the advantage of providing a roughly equal dosages of iodine to all members of a population. The prolonged heating of certain dishes, however, may reduce iodide and iodate ions to yield iodine. Iodine then may be lost by evaporation and sublimation.
In Trampel, (U.S. Pat. No. 4,928,629) a method is disclosed for inoculating soluble materials into an egg. The method involves removal of at least a portion of the egg""s cuticle and then forcing the soluble materials with a pump to penetrate through the pores in the egg shell. This method involves special positive pressure pumps and does not seem suitable for use with large scale batches of eggs.
In Ishikawa and Kamimae, (U.S. Pat. Nos. 4,187,294, 4,394,376, and 4,410,541) iodine-fortified poultry eggs are made by feeding the birds with a prepared feed that contains high levels of iodine. This method has a disadvantage that it requires access to the feed, which makes this method impossible for eggs already obtained from a commercial farm.
In other parts of the world, eggs have been preserved in alkali by coating the egg with a composition comprising principally of wood ash and rice husk. After a few weeks, the white of the egg turns into black, jelly-like substance and the egg yolk also turns dark with a characteristic smell of ammonia.
In addition, eggs have been preserved by table salt (sodium chloride) since ancient times. After a few weeks of pickling in brine, the salt would penetrate across the egg shall into the egg, making the egg, especially the egg white, taste salty.
This invention relates to the method of fortifying eggs, especially avian eggs, with iodine. Eggs are dipped in a bathing composition or solution comprising iodide or iodate salts of alkali or alkali earth metals at an effective concentration for a duration of between a few seconds to a few days, in order to produce an adequate internal iodine concentration of iodide or iodate salts. The iodine fortified eggs may then be considered a dietary supplement for humans or animals.
Accordingly, it is the object of this invention to provide a method of fortifying eggs with iodine. This method provides the surprising result that the iodine is found to concentrate in the egg yolk as opposed to the albumen. This may be useful in the subsequent preparation of food where only the egg yolk is used, for example as an emulsifying agent in salad dressings.
It is also the object of this invention to provide a heat-stable vehicle for iodine oral administration. The fact that iodine is found to concentrate in the yolk makes it more difficult for iodine to leave the egg during cooking.
It is also the object of this invention to provide a method to supplement dietary intake of iodine without added sodium chloride, thus being suitable for people who, for personal, medical, or cultural reasons, prefer to be on low salt diet.
Another object of the invention is to provide methods where iodide or iodate salts of alkali or alkali earth metals may penetrate the pores of egg shells without breaking the egg shells. The eggs that have gone through this procedure will be indistinguishable by consumers from untreated eggs.
Yet another added benefit of the invention is that several types of microorganisms that exist on the egg cuticle, which are susceptible to iodide or iodate salts of alkali or alkali earth metal at the concentrations used, will be eliminated. Lowering the number and types of microorganisms on the egg cuticle should help lengthen the shelf life of the treated egg.